MEASURING DEVICE FOR PARTICLE CONCENTRATION/PARTICLE SIZE DISTRIBUTION IN GAS FLOW

摘要

PROBLEM TO BE SOLVED: To accurately and easily measure the concentration of particles and a particle size distribution in an air flow by inputting signals received from a measuring instrument, a flow meter or the like, and calculating the concentration of particles or the like in the gas flow running through a main flow tube. ;SOLUTION: A sampling tube 5 is inserted in a main flow tube 1, so as to keep a sampling port 4 at a suitable position in the main flow tube 1, and a suction device 7 is operated at the preset suction flow velocity. As a result, particles 2 are drawn at a main flow velocity and a suction velocity in an unequal suction state, and a measuring instrument 8 finds a particle collected weight Mi per unit time via a particle collector 6. Also, a suction flowrate Vi per unit time is measured with a flow meter 12, and a computing element 10 makes a correction for temperature on the basis of a temperature signal 20 sent from a temperature detector 19. Furthermore, a suction velocity is found from the suction flowrate Vi, the cross sectional area S of the bore of the sampling port 4 and a suction time. Particle concentration Ci in this case is obtained from the collected weight Mi and the flowrate Vi according to the expression of Ci=Mi/Vi.;COPYRIGHT: (C)1997,JPO